is the metal shroud hot?

*o* · Post by ***o*** » Thu Apr 14, 2005 10:44 pm

hi everyone not quite the same thing but ill ask it anyway

i have gota a cooling fan *gasp* and i just want to check if itll work it says 12vDC 1.1w willl this be fine?

nos_slived · Post by **nos_slived** » Thu Apr 14, 2005 11:23 pm

It should. Try it on your battery before attaching it though.

Code: Select all

W=EI
I=W/E
I=1.1/12=0.09167A=91.67mA

Very little draw at 12V. If you had an 8V input, it would probably still work, but will draw a bit more current (137.5mA to be exact).

*o* · Post by ***o*** » Thu Apr 14, 2005 11:27 pm

ok thanks i have all my parts now time to begin

*o* · Post by ***o*** » Fri Apr 15, 2005 4:53 pm

ok another power question i have a car adaptor that says it is 12v-3v 800ma will this work for my 3v line and what would happen if i use this will it destroy my beloved n64?

Post by **gannon** » Fri Apr 15, 2005 4:56 pm

You'd need 2 of those in parallel to power the 3.3V line of the n64.

*o* · Post by ***o*** » Fri Apr 15, 2005 5:00 pm

damn it! could i just use a resistor to step down the power?

Post by **bicostp** » Fri Apr 15, 2005 6:29 pm

gannon wrote:You'd need 2 of those in parallel to power the 3.3V line of the n64.

I think he means the power thing doesn't put out enough current for the N64. Stepping down the power would be the exact opposite of the solution you need.

gannon (or whoever knows the electronics formulas): series (daisy-chained)= Volts + Volts, Parallel (connected individually) = amps + amps, right?

*o* · Post by ***o*** » Fri Apr 15, 2005 6:46 pm

RPGTKnicks guide says you need a 12v-3v 1amp transformer so if i use 800ma will it destroy my $20 n64

nos_slived · Post by **nos_slived** » Fri Apr 15, 2005 6:47 pm

You got it BCP

!

Yea, don't step down your voltage, because 3V is about the minimum that it can run on. By running 2 of those in series, or using a 3V converter with a higher current rating.

It probably won't destroy it, but your system probably won't work properly without high enough current, and you would probably burnout the converter with a 1A load, which could end up causing 12V to go right through.

*o* · Post by ***o*** » Fri Apr 15, 2005 6:48 pm

lol i mean can i take the 12v line put resistors on it and make it a 3v line with enough current?

nos_slived · Post by **nos_slived** » Fri Apr 15, 2005 7:04 pm

I guess using a 3ohm resistor would work (R=3V/1A).

Make sure that your resistor is rated for 12W or higher, or else you will have to run the resistors in parallel. If you do go in parallel, make sure that you multiply 3ohms by the number of resistors in parallel. For example, if your resistors were rated for 3W, then you would need 4 or more resistors in parallel (12W/3W=4). In this case, lets just say that you want to be safe, so you use 6 resistors. Each will have to be 18ohms (R=3ohm*#).

Post by **gannon** » Fri Apr 15, 2005 7:06 pm

no, that would create a linear output voltage that doesn't stay the same.

nos_slived · Post by **nos_slived** » Fri Apr 15, 2005 7:20 pm

OOH CRAP! What was I thinking. I'm kind of out of it right now (to much time around Cennar). I forgot that as the battery runs down, you lose forward voltage.

The best thing to do I think, would be to use a few regulators.

monster · Post by **monster** » Fri Apr 15, 2005 7:23 pm

i'm looking for a uber-high effeciency regulator, but all the ones i find are SMD or DIP, what kind of package are the ones with three pins sticking out of one side?

i need a 12V, 3.3V, and a 7.5V. as high effeciency as possible

HK-47 · Post by **HK-47** » Fri Apr 15, 2005 7:25 pm

TO-220